“Heart failure readmission is one of the most common cardiac-related readmissions within the first year after TAVR.”

Aishwarya Bhardwaj, MD, Medical resident, Department of Medicine

Jacobs School of Medicine and Biomedical Sciences

BUFFALO, N.Y. — As more elderly patients undergo the
minimally invasive heart valve procedure called Transcatheter
Aortic Valve Implantation (TAVR), concerns have been raised as to
what causes some to be readmitted for heart failure after the
procedure.

Now, University at Buffalo researchers, working in the Gates
Vascular Institute, Kaleida Health, have published a paper
that identifies a new way to predict which patients may be at
higher risk.The paper was published online on Aug. 21 in Structural
Heart: The Journal of the Heart Team. First author is Aishwarya
Bhardwaj, MD, a medical resident in the Department of Medicine in
the Jacobs School of Medicine and Biomedical Sciences at UB.
Tharmathai Ramanan, MD, clinical cardiovascular disease fellow at
UB, is first co-author. Vijay S. Iyer, MD, PhD, associate professor
in the UB Department of Medicine, is principal investigator. All
see patients through UBMD Internal Medicine.

TAVR is a minimally invasive procedure reserved for patients who
have been turned down for a traditional aortic valve replacement by
open heart surgery due to serious medical co-morbidities.

“For many patients, TAVR is a life-saving and
life-enhancing procedure and most see significant improvements in
their symptoms,” said Bhardwaj. “However, a small
percentage may not benefit adequately with the procedure. Heart
failure readmission is one of the most common cardiac-related
readmissions within the first year after TAVR.”

To find out what might be putting these patients at higher risk,
Bhardwaj and her colleagues conducted a retrospective study on 198
patients (mean age was 82 years) who underwent TAVR from 2012-16 at
the Gates Vascular Institute in Buffalo.

Prognostic marker for heart failure

They focused on a measure called elevated valvuloarterial
impedance, also known as Zva, which is obtained noninvasively by a
cardiac ultrasound. Zva incorporates both the aortic valve stenosis
and the resistance encountered by the heart due to thickening of
the arteries and blood vessels for pumping blood in the
body.

While Zva has been shown to have prognostic significance in TAVR
patients, there was no quantifiable data as to how useful it might
be in predicting heart failure, Bhardwaj explained.

“Our study was the first to evaluate the role of Zva,
which can be easily obtained non-invasively for predicting
heart failure readmissions,” she said. “Identifying
such prognostic markers would help reduce rehospitalizations and
would eventually translate into reduced health
care expenditures as well.”

The UB study found that among 41 patients who were
rehospitalized after TAVR, nearly twice as many patients (34.2
percent vs. 18.1 percent) with a high Zva prior to undergoing TAVR
were readmitted to the hospital after TAVR because of heart failure
symptoms.

Another key finding was that patients in whom the Zva either
increased or remained unchanged were three times more likely (18.2
percent vs. 6.3 percent) to die within one year of the
procedure.

“For that reason, we recommend that Zva should be
integrated as part of routine follow up post-TAVR,”
Bhardwaj said, “and should be obtained serially during
follow-up echocardiograms (ultrasounds of heart) for
monitoring risk of heart failure readmissions.”

Determining who may not be a candidate for TAVR

Bhardwaj and her co-authors note that Zva may also have
relevance to determining who should and should not undergo TAVR in
the first place.

“Our findings suggest that Zva may play a key role in
patients who fail to have clinical improvement post-TAVR and will
most likely not benefit from the procedure,” she said,
“so Zva has prognostic implications in evaluating
patients who may or may not benefit with the procedure.”

The importance of such risk stratification has a significant
impact, the authors said, as hospital administrations nationwide
work to minimize heart failure readmissions while trying to
identify patients at higher risk to utilize more resources in the
outpatient setting.

“Zva can be utilized to identify patients at high risk for
readmissions and accordingly, help divert resources to these
patients by establishing transitional care programs and close
cardiologist follow up in order to avoid readmissions in
hospital,” Bhardwaj concluded. “This should translate
to potential cost-savings and reduced health care
expenditures.”

The researchers are now incorporating the Zva with novel indices
on echocardiography on patients undergoing TAVR at the Gates
Vascular Institute.